Multichannel glutamate monitoring by electrode array electrochemically immobilized with enzymes

We developed a novel method for the fabrication of a multichannel glutamate sensor based on a planar electrode array. By scanning and holding the elec trode potential in a solution containing glutamate oxidase and a polymer to which horseradish peroxidase and electron-transfer mediator were bound, we successfully immobilized these enzymes and a mediator on the electrodes of the electrode array through electrochemical deposition of the polymer. We confirmed the resulting sensor possessed high sensitivity and selectivity t o glutamate. This multichannel sensor may be useful for the non-invasive, r eal-time monitoring of the glutamate distribution in biological samples.